Wireless telegraphy.



No. 706,500. Patented Aug. 5, |902. y

H.. SHOEMAKER. WIRELESS TELEGRAPHY.

(Application led M'iy 10, 1902.1 (lo Model.)

I I U fmoemto Maa- ' @IHM/neig UNITED STATES VPATENT OFFICE.`

HARRY SHOEMAKER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR TO MARIE V.GEHRING AND THE CONSOLIDATED WIRELESS TELEGRAPI-I AND TELEPHONE COMPANY,OF PHILADELPHIA, PENNSYLVANIA.

WIRELESS TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. r"(06,500, dated August5, 1902.

Original application filed October 25,"1901, Serial No. 79,959. -Dividedandrthis application filed May 10, 1902. Serial No.106,736. (No model.)

To all whom/'it may concern.-

Be it known thatI, HARRY SHOEMAKER, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inWireless Telegraphy, of whichthe following is a specication.

This inventionrelates to improvements in Wireless telegraphy, and hasspecial reference to an apparatus employing a receiver which is operatedby static induction.

Another object of `my. invention is to dispense with the imperfectelectrical contact or coherer as is now used and employ a responsivedevice of a much simpler and more durable construction.

Another object of the invention is the provision of a receiver which mayemploy solely the ground or the air and ground and which may be tuned sothat any number may receive signals from their proper transmitter at thesame time without interference.

To attain the desired objects, the invention consists of a system ofWireless telegraphy embodying novel features of construction andcombination of parts, substantially as disclosed herein.

In the drawings, Figure lis a diagrammatical view of the entirereceiver, having two ground connections. Fig. 2 is a similar view, on asmaller scale, with an air andl ground connection. responsive device,and Fig. 4; is a bottom plan View thereof.

My receiving apparatus consists of the ground 1, to which is connectedthe wire 2, the batteries 3, wire 4, and the cap 5 of the responsivedevice. This cap 5 clamps and holds the ferrotype-diaphragm 6 in place,and

secured to this cap is the rubber cup 7, the

wirei being also connected to the diaphragm. Mounted upon the posts 8 isthe strip 9 of mica or any resilient insulation material. This strip isso mounted as to be free to vibrate at a certain period or pitch,depending upon its length. Carried by this strip by means of a post 10is a metal plate or disk 11,

Fig. 3 is a sectional view of the' i tive contact.

which is free to vibrate :with the strip and rests adjacent to thediaphragm. Connected to the strip and also with its post 10 by means ofa Wire 12 is a spring-pointer 13, which is connected to a post 14., thusgiving thepoiuter a slight spring motion, and upon its free end iscarried the double-headed contact-point 15, which is adapted to alwaysslightly contact one of the. points 16 or 17, which, with the wires 18,battery 19, relay 20, wire 2l, and the pointer, make a circuit. An adjusting-screw 22 is employed to vary the pressure of the spring-pointer.I also employ the resistance 23, which is non-inductive and takes up theself-inductance of thev relay. The armature 24. controls the, sounder 25through its circuit 26 as the contact at 15 and 1o and 17 is made. i

From the foregoing description, taken in connection with the drawings,the operation of my improved receiver is readily linderstood, but,brieiiy stated, it is as follows: As thetransmitter employing any'formof energy is operated electrostatic Waves .are sent through the groundand are radiated over the surface of the vearth in much thesame manneras ripples in a pond when a stone is thrown therein-that is, it variesthe potential at different points in its path. When these waves reachthe receiver, a change of potential is caused at the receivers grounds,causing variations of potential between the diaphragm 6 and the disk 11,thus causing the disk 11 to vibrate the pointer which controls the relayas the points make a posi- The relay thus being operated operates therecorder-circuit and the signal as received. With this form of receiverit is possible to operate a great number of transmitters and receiverswithout interference, as

the disk l1 has a certain natural period of vibration. If the impulsesare sent in the same period as the natural period of the strip 9, theplate carried thereby will get its maximum swing, hence will record thecharacter sent. Should the periods of the transmitter :not be the sameas the strip, the strip will not get its maximum swing, but will nodoubt be ing about one thousand volts.

elected to a certain extent, such extent, however, not being enough torecord the characters. The apparatus in the transmitter for furnishingthe varying potential should have the same period as the strip 9. Thebattery of the receiver is of a very high potential, be-

The reason for this highvoltage is to keep the diaphragm 6 under astatic field, thus making the same more sensitive in the same manner asthe common magnetic field in magneto -telephones makes them moresensitive.

This application isa divisional application which was originally coveredand set forth in application for Wireless telegraphy, iiled October 25,1901, Serial No.`79,959.

I havev found by experimenting that the grounds of the transmitterv andreceiver should be substantially the same distance apart-say from twentyto thirty feet-andthat the distance between the diaphragm 6 and the disk11 should not be over one-eighth to one-fourth of an inch.

What I claim as new, and desire to secure by Letters Patent, is-

l. A receiver, which comprises a plurality of plates in inductiverelation, means for permanently charging the plates and a local circuitcontrolled by said plates.

2. A receiver, which comprises a plurality of plates in inductiverelation, a source of high-potential energy in connection with opposingvplates through an earth-circuit.

3. A receiver, which comprises opposing plates, a high-potential sourceof energy connected to said plates through an earth-circuit topermanently charge ythe same, and a circuit-controlling means operatedby the reaction between said plates upon the reception of a signal.

4.' .A receiver, which comprises plates in inductive relation' to eachother, means for normally charging said plates to a high potential,means controlling a local signal-circuit operated upon fiuctuations ofcharge on said plates due to received signal energy.

5. A receiver, which comprises a plurality of plates in inductiverelation, batteries of high potential permanently charging the plates,and a local circuit controlled by said plates.

6. A receiver, which comprises a plurality of platesin inductiverelation, a battery of high-potential venergy in connection withopposing plates of4 an earth-circuit.

7.- A receiver, which comprises opposing plates, a battery of highpotential connected to said plates through an earth-circuit toperkmanently charge the plates, and a circuitcontrolling means operatedby the reaction 6o of plates in inductive relation to each other,

a battery for normally charging said plates to a high potential, meanscontrolling a local signal-circuit operated upon fluctuations andcharged on said plates due to received signal energy.

9. A receiver, which comprises a plurality of plates in inductiverelation, batteries of high potential permanently charging the plates,means kept under an electrostatic field interposed between saidbatteries and one of the plates, and a local circuit controlled by saidplates.

10. A receiver, which comprises a pluralityl of plates, a high-potentialsource of energy connected to said plates and an electrostatic meansinterposed between one of the plates and the high-potential source ofenergy.

l1. A receiver, which comprises a plurality of plates, a high-potentialsource of energy connected to said plates, an electrostatic meansinterposed between one of the plates and the source of energy, and arecorder instrument controlled by said means.

12. A receiver, which comprises a plurality of plates, a source ofhigh-potential energy connected to said plates and an electrostaticmeans interposed between one of the plates and the source of energy, arelay-circuit controlled by said means and a recorder-circuit controlledby said relaycircuit.

13. A receiver, which comprises a plurality of plates, a diaphragmsurrounded by insulation connected to one of the plates, a battery ofhigh potential interposed between the plate and diaphragm, a diskadjacent to the diaphragm and connected to the other plate so as to bekept under an electrostatic field, and a recorder controlled by saiddisk.

14. A receiver, comprising a plurality of ground-plates, ahigh-potential source of energy interposed therebetween, a diaphragmconnected directly with the source of energy, a disk mounted so as tobefree to vibrate adjacent to said diaphragm and kept under anelectrostatic influence by said source of energy, said plate or diskbeing directly connected to the other of the ground-plates and arecorder-circuit controlled by the disk.

In testimony whereof I afl-lx my signature in presence of two witnesses.

HARRY SI-IOEMAKER.

Witnesses:

FREDK. W. MIDGLEY, OHAs. J. FOREMAN.

IOO

IlO

